Water cooled packing and pusher rod



y il, @4 G. P. LEssMANN 2,208,373

WATER COOLED PACKING AND PUSHER ROD Filed Aug. 17, 1938 I 2 Sheets-Sheet l P4 rF 60 7/ n 1 59 f6? Ll-- l? ,/P 6. 30

Figi 2 l "ff" I I WITN ESSES: INVENTOR Gerhard Plessm ann.

@ma/{ZMM BY ATTORNEY july i6, 19%. G. P. LEssMANN 2,208,313

WATER COOLED PACKING AND PUSHER ROD Filed Aug. 17, 1938 2 *Sheets-Sheet 2 Fly 3.

WITNESSES: INVENTOR v Gerhard Pessmahn. M/XZM/M WMM ATTORNEY Patented July 16, 1940 UNITED STATES PATENT OFFICE WATER COOLED* PRAgKING AND PUSHER of Pennsylvania Application August 17,

13 Claims.

In certain types of heat-treating, batch-feed furnaces, the charge is moved in the furnace by means of some manipulating tool usually in the form of a pusher rod extending through a Wall of the furnace. My invention relates specifically to a pusher rod assemblage and housing therefor applicable primarily to a batch-feed furnace in which the charge must be heat-treated at a high temperature, or must be heat-treated While enveloped by a protective or inert atmosphere, or both; although in a broader sense my invention is applicable to any furnace requiring a manipulating tool extending through a Wall thereof, and having a charge engaging device inside the furnace and an operating means, manual or powerdriven, on the outside.

Where high temperatures are created inside the furnace, it is desirable to cool the pusher rod in order to minimize the use of expensive heat-resistant metal alloys and also to ensure satisfactory operation over extended periods of time. Where a protective atmosphere is e-mployed in the furnace, it is desirable to` encase the furnace in a metallic shell construction thereby rendering the furnace impervious to gas by preventing seepage of the gas beyond the porous insulating rebrick constituting the walls thereof. A seal is also desirable Where the pusher rod passes through the furnace Wall to prevent leakage of gas and to lubricate the pusher rod. Where both high temperatures and a protective atmosphere exist in the furnace, it is desirable to keep the seal cool in order that its efficacy be not impaired by the heat.

35 It is accordingly a broad object o-f my invention to provide a structure which Will maintain coc-l a charge-manipulating tool passing through a furnace Wall, more specifically, a pusher rod.

An additional object ancillary to the preceding 40 object is to .accomplish the cooling Without the use of moving pipe connections.

It is a primary object of my invention to construct a pusher rod that may be effectively cooled Without excessive loss of heat.

45 An additional purpose of my invention is to prevent leakage of gas through the opening in the furnace wall through which the tool passes, and specifically this is accomplished by a packing seal .about the tool or rod substantially at the exterior surface of the furnace.

A further purpose of my invention is to employ the afore-said seal as a lubricating means for the moving manipulating tool or pusher rod.

It is an additional object of my invention to maintain the aforesaid seal GC01 so that its ef- 1938, Serial No. 225,391

(Cl. 214-23) f cacy both as a seal and as a lubricating means is maintained against the deteriorating and destructive action of heat. Y

It is an overall object of my invention to accomplish the above and other objects by .a structure which is simple in construction, economical to manufacture and assemble and will require little attention with continuous operation over extended periods of time.

My invention has other objects not specifically stated above, which will be apparent from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a longitudinal sectional View of a furnace With the pusher rod and means to cool the same in horizontal view.

Fig. 2 is a vertical sectional view of the pusher rod and gland on an enlarged scale With some parts in elevation.

Fig. 3 is a side view of a guide for the operating mechanism for the pusher rod.

Fig. 4 is an enlarged sectional View taken on the line IV-IV of Fig. 2.

Fig. 5 is an enlarged sectional view taken on the line V-V of Fig. 2.

The manipulating tool of my invention is applicable to any appropriate type of furnace requiring the pushing or movement of the charge by a manipulating tool. In View of this fact, I show in Fig. 1 the furnace generally indicated by the reference number 2 in a schematic manner, and

I have chosen an extremely simple construction of the furnace since this feature is only of minor importance with respect to my invention and it is desired to make more prominent the construction of the manipulating tool, its support and their relation to the furnace Which constitute the essence of the invention.

The furnace 2 has Walls 4 constituting a heating chamber 6. Heating units (not shown) which may take the form of electric resistance elements, or metallic tubes heated to radiance by the burning of combustion gases therein, or any other suitable heating means, may be employed to raise the temperature of the heating chamber 6. On the other hand, the chamber 6 may be a cooling chamber in certain types of furnaces or heattreating processes, and I do not desire to be limited to a pusher rod employed in a heating chamber only,

The charge can enter and leave the chamber 6 through appropriate doors not shown. In any event the charge Within the furnace may be positioned either during its entrance, or its exit, or during the heat-treating process by a manipulating tool indicated in its entirety by reference character 8.

In the event the heat-treatment process of the charge requires a protective atmosphere within the chamber ii, it is preferable to encase the furnace walls in a metallic shell lil. This metallic sheli is impervious to gas so that any protective atmosphere seeping through the porous rebrick and insulating walls Il cannot escape through the furnace via the walls thereof.

The manipulating tool 8 extends through an opening in one of the walls of the furnace, and comprises a metal tube ill which may be of steel, or any other appropriate metal or .alloy may be employed such as, for example, a nickel-chromium-iron alloy when high temperatures are encountered. Attached to the end of the tube H towards the inside of the furnace is a head supporting member it which is also tubular and of somewhat less diameter than the vtube lll. As shown, the supporting member i6 is formed with a shoulder li about which the tube it nts and a weld joint i3 makes the parts, in effect, unitary. Supporting member it supports a charge manipulating head i9 which may take any appropriate form depending on the manner in which the charge is to be manipulated. The supporting member i6 has an aperture 2S in its upper Wall and a headed pin 22 ts into this aperture and a corresponding aperture in the top of the head I9 whereby movement of the pusher rod it Will carry with it the head i9. The supporting member i6 is closed at its furnace end as shown at 23 to prevent the entrance of hot air into the hollow portions of the pusher rod.

The other end of the tube l@ is closed by a solid cylindrical member 2li of substantially the same external diameter as the tube lll except for a protruding step 25 snugly tting into the tube It. A weld joint 25 also makes the cylinder 2t,

in effect, unitary with the tube lli.

The tube it, the supporting member I6, the headlg and the closure 2Liconstitute the pusher rod 8 which is' deliberately made hollow to decrease the heat flow from the head along the remaining portions of the rod.

In order to guide and cool the pusher rod 8, a cylindrical water jacket, indicated in its entirety by the reference character 28 is embedded in a wall of the furnace and comprises an internal wall 3@ having a central bore snugly fitting about the tube ifi, a spaced external wall 32, and end walls 3ft and Sii. lThe Walls Sil, 32, t@ and 36 form a hollow chamber 38 through which cooling fluid may be passed for the purpose of cooling the tube lll. To facilitate the ingress and egress cf the cooling liquid to land from the chamber 33, the wall 35 is provided with an inlet pasage 4f! and an outlet passage l2 in which may be screwed pipe elbowsy #it and 46, respectively.- Appropriate pipe connections to these elbows. control the flow of cooling fluid to the water jacket.

I prefer to have the furnace wall protect the end of the water jacket from thedirect heat in the heating chamber E5 and this is accomplished by iirebrick llt.

An annular ring 5E! is welded as shown at y5l to the jacket at the exterior thereof and this ring is clamped by means of bolts 52 to the shell lil with an asbestos lgasket 53 interposed therebetween in order to seal the jacket and wall against leakage oi gases.

It is also necessary to provide against leakage of the protective atmosphere from the chamber E along the outside surface of the `tube I4 and the inside surface of the wall 30. To accomplish this the water jacket has a shoulder 54 cut into the end wall at the portion away from the heating chamber. This shoulder is packed preferably with a graphited, lubricated, square-braided asbestos filler 5t, which is pressed into a compact seal by means of a gland, comprising a l sleeve et about the tube ld and an apertured plate G2 unitary with the sleeve, which is pressed against the ller seal 5t by means of bolts and nuts 6@ and 55, respectively, the bolts- 64 being secured in suitable holes in the end wall 36 of ie water jacket 23, although any other appropriate construction may be employed. I prefer to taper the shoulder 54 outwardly as shown at ported at one end by plate 'l2 Secured to stationary I-beams lll. Sliding on the guide rods 10 is a guide 'lihaving an internal bore 18 which fits about-the pusher rod A pin fits into aligned apertures in the guide 'i6 and in the rod t. IIhe guide is reciprocated by means of a reciprocating mechanism not shown operating upon a rod 82 secured to the guide 16. The guide 'l5 has appropriate apertures 84 sliding upon the guide rods li).

In the operation of the specific manipulating tool shown in the drawings, the pusher rod 8 will position any charge placed in front of its head i9 by an inward movement thereof, the rod being withdrawn to permit an additional charge to be placed in iront of the head i9 in any appropriate manner as, for example, by a second pusher rod.

It may be observed that in order to preserve the efficacy of the seal 56 as a seal andas a lubricating means for ther rod 8, it is necessary to maintain the seal at a low temperature or otherwise the lubricating oil with whichr the seal is saturated Would rapidly decompose, or deteriorate, or both. By providing the water jacket about the rod S, the various increments of the rod are cooled to a sufficient degree before they contact the seal 56, and in this way I ensure not only a life for the seal, but also a tight, lubricated joint preventing leakage of gas through the opening in which the rod slides.

An important aspect of my invention lies in the provision of a skeleton structure for the pusher rod. By decreasing the amount of metal comprising the pusher rod, as well as keeping the air or atmosphere within it inert, I am able to decrease the amount of heat that must be absorbed by the cooling fluid flow through the jacket 28 and still attain the requisite low temperatures at the'seal 56. Moreover, the cooling rof the rod itself with a minimum loss of heat is obviously an exceptional advantage if the chamber ii is subjected to high temperatures, 'I'he close fitting jacket diverts the largest amount of heat possible by simple means, and this heat comes substantially entirely from the pusher rod inasmuch as the furnace wall protects the jacket from the direct heat in the chamber 6.

While I have shown and described my invention in the form which I now believe to be the best mode of application thereof, it is obvious that many changes may be made Within the spirit and scope thereof. Thus, for example, the particular cross-sectional shape of a pusher rod and surrounding jacket may be Varied as desired and can be square instead of round. It is, therefore, desired that the appended claims be given their broadest construction and limited by the prior art.

I claim as my invention:

1. In a furnace having a gas-impervious wall comprising non-metallic refractories covered by a metallic-shell, and provided with an opening, and preferably of the type permeated by a protective atmosphere and in which a charge is moved inside the furnace, a Ycharge manipulating tool extending through said opening and adapted to be reciprocated to move a charge in the furnace. means about said tool for guiding it, means in said wall for cooling said tool, the last said means being embedded in the first said wall so that it is insulated from the direct heat inside said furnace, and sealing means at the outer side of said wall for preventing leakage of gas between said guiding means, said tool, and said wall.

2. The structure of claim 1 characterized by ypart of said sealing means being in contact with said tool on the portions cooled by said cooling` means and lubricating said tube to permit ready movement of said tool with respect to the seal.

3. In a heat-treatment furnace having a Wall comprising non-metallic refractories and provided with an opening, said furnace being preferably of the type in which a protective atmosphere is employed and in which a charge is moved inside the furnace, a metallic jacket in said wall having a bore aligned with said opening, said jacket extending partially into said wall from the outside so that it is insulated from the direct heat inside said furnace, an elongated hollow tube fitting said bore and adapted to be reciprocated, a charge-manipulating head on the end of said tube towards the interior of said furnace, means closing said tube, said jacket being hollow with an inlet and an outlet for the passage of a cooling iiuid therethrough, and a packed seal means to prevent leakage of gas between said jacket and tube and on the exterior side of said jacket and said wall.

4. The structure of claim 3 characterized by the said seal lubricating said tube. i 5. In a heat-treatment furnace having a gasimpervious wall comprising non-metallic refractories covered by a metallic shell, and provided with an opening, the furnace being preferably of the type in which a protective atmosphere is employed, and in which a charge is moved inside the furnace, a guide in said wall and having a lbore aligned with said opening, a seal between said guide and said Shell against leakage of gas fluid therebetween, an elongated hollow tube tting said bore and adapted to be reciprocated through said opening and in said guide, cooling means for cooling said tool and said guide, embedded in the first said wall so that it is insulated from the direct heat inside said furnace, a closed charge-manipulating head on one end of said tube, closure means on the other end of said tube, and a lubricating seal against leakage of gas fluid between said tube and guide, said seal being towards the outside surface of the furnace whereby the cooled hollow tube keeps down the heat flow from the said head to the last said seal. 6. In a heat-treatment furnace having a gas impervious wall comprising non-metallic refractories covered by a metallic shell, and provided with an opening, the furnace being preferably of the type in which a protective atmosphere is employed and in which a charge is moved inside the furnace, a hollow guide and jacket member in said wall comprising two concentric cylindrical walls and two end walls forming an enclosed chamber with a central bore aligned with said opening, said member being embedded in the first said wall so that it is insulated from the direct heat inside said furnace, a cooling liquid inlet and outlet to said chamber, a seal against gas leakage between said member and said shell at the outer and cooler end of the iirst said wall, a charge-manipulating rod adapted to be reciprocated, fitting said bore and extending through said bore and opening, a lubricating packing between said rod and jacket and towards the outer portion of said jacket, and a sleeve about said rod and pressing said packing against said jacket and said rod.

'7. The structure of claim 5 in which the said rod comprises an elongated hollow tube with a closed pusher head on the end of said tube towards the interior of the furnace, said tube being closed at its other end.

8. A heat-treating furnace having walls deiining a chamber, said walls comprised of nonmetallic refractories and covered by a gas-impervious metallic shell, one of said walls having a stepped opening comprising a smaller and larger hole with the said smaller hole toward said chamber, said shell having a hole substantially corresponding to the said large hole, a charge-manipulating tool adapted to move a charge in said furnace comprising a rod substantially fitting said smaller hole, and slidable in said opening, and means including a chambered cooling jacket in said larger hole for cooling said rod and guiding it.

9. The structure of claim 8 including gas-sealing means between said jacket and said shell.

10. The structure of claim 8 including gassealing means between said jacket and said shell, and a lubricating, packing gland co-operating with an exterior portion of said jacket to provide a gas seal between said rod and jacket.

11. A heat-treating furnace having walls de-4 ning an interior chamber, said walls comprised of non-metallic refractories, a cooling jacket in one of said walls comprising an inner, tubular member, a larger outer member, and end members, said members defining cooling fluid paths in said jacket, one member of said end members being disposed toward the outside of said one wall and having cooling fluid inlet and outlet means extending outwardly, a charge-manipulating tool fitting said inner member and movable therein, and having a head for moving a charge in said chamber, a gas-sealing gland about said tool and fitting an outer shoulder in said inner member, said gland including a compressible substance and a sleeve, a clamping plate for said sleeve, and a plurality of tightening means for said plate, and secured to said one end member, extending outwardly therefrom.

12. A heat-treating furnace having walls defining an interior chamber, said walls comprised of non-metallic refractories covered by a gasimpervious, metallic shell, a cooling jacket in one of said walls comprising aninner, tubular member, a larger outer member, and end members, said members dening cooling iiuid paths in said jacket, one member of said end members being disposed toward the'outside of said one Wall and having a flange extending beyond said outer member, means including a gas seal between said :iemgen and said shell, a charge-manipulating tool tting said inner member and movable therein,

ysind having a head for moving a charge in said chamber, e, gas-sealing gland about said tool and fitting an outer shoulder in said inner member, said gland including a. compressible sub-stance and a sleeve, a clamping plate for said sleeve,

GERHARD P. LESSMANN. 

